Astrophysics News & Events

Abstract: The discovery of nearly 2000 extrasolar planets has given us the opportunity to thoroughly study their host stars. The determination of chemical abundances provide us with unique information not only about the stellar atmospheres but also about the processes that take place inside the stars and how they have been formed. The first difference we came across between stars with and without planets was that the former are on average more metallic but other interesting trends have been reported during these years. I will make a short review about these studies and focus on the latest results obtained by our group.

Abstract: Sun-like oscillations have been discovered in five hundred main sequence and sub-giant stars and in more than twelve thousand red giant stars in the solar neighbourhood. In this talk, I will argue how this network of natural detectors could be used to probe fundamental physics, including dark matter and gravitational waves. Moreover, these star detectors can complement the experimental research done on Earth. Moreover, this observational network of stars could be used to make other type of gravity tests, as unlike experimental detectors, it should be possible to follow the progression of gravitational waves throughout space. The continuous observation and monitoring of the oscillation spectra of the stars around us, within a sphere of up to one thousand parsecs, could help on the discovery of gravitational waves originating in our Galaxy or even elsewhere in the Universe.

Abstract: The existence of powerful AGN has now been established well within the first Gyr of the Universe, through the observations of tens of QSOs up to the currently highest redshift of z ∼ 7 and theoretical work that shows how such super-massive (M∼ 10^9 M⊙) black holes can exist at such early epochs. In particular, these results imply that radio powerful sources should exist at very high redshifts (z > 7), even if all efforts to detect them have so far been unsuccessful. Over the coming years, powerful new facilities like the JVLA, GMRT, LOFAR, and the several upcoming SKA pathfinders experiments (ASKAP, MeerKAT, WSRT-Apertif) will dramatically increase our knowledge of the Radio Universe. Revolutionary deep-wide radio surveys like EMU, WODAN, or LOFAR will cover the sky at extreme depths over unprecedented large areas, and the first radio galaxies of the Universe should be finally identified. In this talk I will discuss our efforts to identify the earliest radio monsters of the Universe, and how the upcoming generation of full-sky deep radio surveys will lead to the discovery of the first radio galaxies, overcoming the limitations found in the deepest radio observations currently available.

Abstract: In the current paradigm, AGNs are galaxies that harbour in their centre super massive black holes, the later being the main engine that explains the multi-messenger and extreme nature of these objects. In this talk I will present recent results from a multi-frequency study of radio loud AGNs, and summarise work in progress in the framework of the Gaia (ESA) mission and the Square Kilometer Array pathfinders.

Abstract: In a number of very exciting present and future astrophysical challenges, such as the detection of ExoEarths and the characterization of their atmosphere, high resolution infra-red spectroscopy provides an invaluable help. However, in this domain, the telluric contamination is a major limitation that needs to be addressed thoroughly. We need no less than a full, accurate and detailed knowledge of the earth atmosphere transmission at the time and location of the observations and in the direction of the target. In this talk, we will show the reasons why this is best done by modelling the earth atmosphere, and why this motivated us to develop the web based platform that will take the name of ULME.

Abstract: The intrinsically faint M dwarfs are the most numerous stars in the Galaxy, have main-sequence lifetimes longer than the Hubble time, and host some of the most interesting planetary systems known to date. Their identification and classification throughout the Galaxy is crucial to unraveling the processes involved in the formation of planets, stars and the Milky Way. The ESO Public Survey VISTA Variables in the Vía Láctea is a deep near-IR survey mapping the Galactic bulge and southern plane. The VVV b201 tile, located in the border of the bulge, was specifically selected for the characterisation of M dwarfs.

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